Originally Posted by DanW@FastFord

They aren't the same thing. A tuning box is a very crude way of extracting more power as it 'fools' the ECU into chucking in more fuel. The last thing you want to do with the Mk3's over sensitive injectors is to throw more fuel in than it expects. If you've seen the price of a new set of injectors you'll know why.

A proper remap is the way forward. You will get more power and mpg, but not both at the same time. Think of it as 'optimising' the engine.

Yes more torque will finish the DMF/Clutch off more quickly, but it's not going to happen overnight if it's in good order. Avoid booting the car in the the first two gears, and don't drive under 1500rpm and you'll keep the drivetrain happy.